Endocytosis of junctional cadherins in bovine kidney epithelial (MDBK) cells cultured in low Ca2+ ion medium - PubMed (original) (raw)

Endocytosis of junctional cadherins in bovine kidney epithelial (MDBK) cells cultured in low Ca2+ ion medium

J Kartenbeck et al. J Cell Biol. 1991 May.

Abstract

The release of intercellular contacts in MDBK cells, initiated by the depletion of Ca2+ ions from the culture medium, results in the endocytotic uptake of membrane vesicles containing specific membrane constituents of the zonula adhaerens (ZA). During this process the junction-derived, endocytosed vesicles remain associated with the ZA plaque components, while the plaque and its attached actin filaments retract as a whole in a ring-like fashion from the plasma membrane, often accumulating, usually in fragments, in the juxtanuclear cytoplasm. Double-label immunofluorescence microscopy with antiplakoglobin and antivinculin has indicated that both plaque proteins colocalize with the hallmark membrane glycoprotein of this junction type, E-cadherin (uvomorulin). When HRP used as a fluid phase marker is applied to the culture medium, simultaneously with the Ca2+ ion-chelator EGTA, numerous HRP-positive vesicles are found in close association with the dislocated plaque material, suggesting that the HRP is contained in the vesicles formed upon EGTA-induced junction splitting. Immunoelectron microscopy with various cadherin-specific antibodies revealed vesicle-associated labeling, confirming the derivation of these plaque-associated vesicles from the ZA. As the desmosome-specific cadherin, desmoglein, is recovered in another type of junction-derived vesicle, which is characterized by its association with a desmoplakin-plaque, we conclude that the membrane domains of both kinds of junction are endocytosed during Ca2+ depletion but stay in different vesicle populations, emphasizing the selective interaction of the specific cadherins with their respective plaque and filament partners.

PubMed Disclaimer

Similar articles

Cited by

References

    1. J Histochem Cytochem. 1966 Apr;14(4):291-302 - PubMed
    1. J Cell Biol. 1985 Jan;100(1):327-32 - PubMed
    1. J Cell Biol. 1976 Apr;69(1):173-95 - PubMed
    1. Eur J Biochem. 1987 Aug 3;166(3):505-17 - PubMed
    1. Dev Biol. 1987 Dec;124(2):451-6 - PubMed

MeSH terms

Substances

LinkOut - more resources